JPS6353838A - Magnetron device - Google Patents

Abstract

PURPOSE:To enable the disuse of a filter case without a danger of microwave leakage and to minimize a magnetron device, by disposing a cathode stem composing the magnetron device on a cut-out part of a semicircular permanent magnet and shielding the cathode stem side by the use of a shield member and a partial yoke. CONSTITUTION:A shield member 24 is installed on the pariphery of an anode cylinder 1 housing a cathode 9 on its central part and a plurality of anode vanes 4 disposed facing this cathode. Pole pieces 2 and 3 are installed on the upper and lower end parts respectively, and a top end part of a sealing member 5, which is made of non-magnetic metal and composed of a cylindrical part 6 connected with the anode 9 and a flange part 7, is inserted into a cut-out part of a semicircular permanent magnet 18 mounted on the piece 2. Successively, a cathode stem 8 is mounted touching the sealing member 5 and a lead conductor 10 from the stem 8 is connected with a capacitor 22, which perforates a yoke 21, through a choke coil 12. An antenna 17 mounted on the anode vanes 4 is made to perforate the piece 3 and a circular permanent magnet 19, and is connected with a sealing part 16 for an exhaust tube. Thus, a microwave component is shielded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetron devices, particularly compact magnetron devices.

2. Description of the Related Art In conventional magnetron devices, in order to prevent microwave leakage, the cathode terminal lead-out portion and the L connected thereto are
A C filter circuit element is disposed within the filter case.

Problems to be Solved by the Invention In recent years, as microwave application devices such as microwave ovens have become smaller, magnetron devices have also become smaller. However, with the conventional structure in which the cathode terminal lead-out portion and the LC filter circuit element are housed within the filter case, there is a limit to miniaturization.

The present invention seeks to provide a compact magnetron device that does not require a filter case as in conventional magnetron devices.

Means for Solving the Problems The magnetron device of the present invention has a sealing body consisting of a cylindrical portion whose tube axis is approximately L-shaped and a flange-like portion integrally formed at one end of the cylindrical portion. A cathode stem, which is sealed to one end of the anode cylindrical body at a flange-shaped portion and further sealed to the cylindrical portion of the sealing body, is disposed in a cutout portion of the semi-annular permanent magnet, Further, a shield body is fitted and held in the anode cylinder, and works together with the yoke to shield the cathode stem and the permanent magnet.

Function According to the above configuration, leakage microwaves from the cathode stem portion are shielded by the shield body and the yoke, so leakage of microwaves to the outside of the apparatus is prevented.

EXAMPLE Below, a magnetron device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of the main part of this embodiment, FIG. 2 is a partially cutaway side view of the main part, and FIG. 3 is a perspective view of the shield body in this embodiment.

In the figure, 1 is an anode cylinder, and pole pieces 2 and 3 whose diameters are slightly smaller than the outside diameter of the cylinder are attached to both ends of the anode cylinder. Resonant cavities are arranged parallel to the axis and radially. Reference numeral 5 denotes a sealing body made of non-magnetic metal, which is composed of a cylindrical portion 6 whose tube axis is approximately L-shaped, and a flange-like portion 7 integrally formed at one end of the cylindrical portion 6. The flange-like portion 7 of the sealing body 5 is arranged on the pole piece 2, and its peripheral portion is sealed to the peripheral portion of the pole piece 2 and the end portion of the anode cylinder body 1.

A cathode stem 8 is attached to the other end of the cylindrical portion 6 of the sealing body 5 and sealed. 9 is a cathode, which is arranged along the axis of the magnetron tube. That lead M
10.11 is led out parallel to the magnetron tube axis through the through hole of the pole piece 2, arranged in the cylindrical part 6 of the sealing body 5 parallel to its central axis, and further penetrates the cathode stem 8 and is sealed thereto. It is kept in place. Reference numerals 12 and 13 indicate choke coils, which are connected to lead wires 10 and 11, respectively. These choke coils 12, 13 share a central axis, are perpendicular to the magnetron axis, and are arranged symmetrically. 14 is a cylindrical sealing body made of non-magnetic metal, and has a flange-like portion at one end. This flange-shaped portion is placed on the pole piece 3, and its peripheral portion is sealed to the peripheral portion of the pole piece 3 and the end portion of the anode cylinder 1. 15 is a ceramic cylindrical body, one end of which is attached to the end of the sealing body 14, and the other end of which is attached an exhaust pipe sealing part 16. 17 is an antenna, one end is connected to one of the anode vanes 4, and the other end is connected to the pole piece 3.
It is guided out of the anode cylinder body 1 through the through hole, and its tip is connected to the exhaust pipe sealing part 16. Permanent magnets 18 and 19 are arranged on both sides of the anode cylinder 1 so as to surround the magnetron tube axis. One of the permanent magnets 18 has a semicircular shape with a portion cut away. And the sealing body 5
A portion of the cylindrical portion 6 and the cathode stem 8 are arranged in the cutout portion 20 thereof. Note that the sealing body 5 is configured such that its height is lower than the thickness of the permanent magnet 18. The other permanent magnet 19 has an annular shape, and the sealing body 14 passes through its hole. 21 is a frame-shaped yoke,
Together with the permanent magnets 18 and 19, they constitute a magnetic circuit passing through the anode cylinder 1. 22 is a feedthrough capacitor, and yoke 21
The choke coils 12 and 13 have one terminal connected to the other end of the choke coil 12 and 13, respectively. These choke coils 12 and 13 and feedthrough capacitor 22 constitute an LC filter circuit. Reference numeral 23 denotes a plurality of heat dissipating fins, which are attached to the anode cylinder 1, and both ends of which are in contact with the inside of the yoke 21. When the magnetron is operated, the heat generated is mainly transmitted from the anode cylinder 1 to the radiation fins 23, and further through them to the yoke 21.
conduct to. At this time, if cooling air is sent parallel to the radiation fins 23 (in the direction of the paper in Figure 1), the radiation fins 24 and the yoke 2
Heat is removed from 1 and the magnetron device is cooled.

A shield body 24 is attached to the cathode lead-out end side of the anode cylinder body 1. As shown in FIG. 3, the shield body 24 has a short cylindrical part 26 in the center of the substrate part 25, into which the anode cylinder 1 is fitted. A pair of parallel sides each have a narrow contact portion 2 that contacts the inner wall surface of the yoke 21.
7 and 28 are formed by bending. Then, on the parallel sides of the other set, there is a cathode stem 8 and a choke coil 1.
2.13. Wide side plate portions 29 and 30 for electromagnetically shielding the space in which the permanent magnets 8 and the like are arranged are formed by bending in the same direction. That is, the side plate portions 29 and 30 are in contact with the yoke 21 to prevent leakage of microwaves.

In the magnetron device of this embodiment, the cathode stem 8
Microwave leakage through the lead wires 10.11 and 10.11 is substantially blocked by an LC filter circuit consisting of a choke coil 12.13 and a feedthrough capacitor 22. and,
Microwave components that cannot be blocked by the LC filter circuit are shielded by the shield body 24 and the yoke 21,
This prevents leakage to the outside.

Furthermore, since the cathode stem 8 is disposed in the notch 20 of the permanent magnet 18, a filter case unlike conventional devices is not required, and the device can be significantly miniaturized.

Note that if a ferrite magnet is used as the permanent magnet 18, there is a risk that the magnet will absorb microwaves, increase its temperature, and become demagnetized. In this case, by covering the side surfaces of the ferrite magnet with a nonmagnetic metal, demagnetization due to self-heating can be prevented. In theory, if a metal magnet is used as the permanent magnet 18, there is no risk of such a problem occurring. Furthermore, since the cathode stem 8 is disposed in the cutout portion 20 of the permanent magnet 18, a filter case is not required, and the device can be significantly miniaturized.

Effects of the Invention The present invention has a structure in which the cathode stem is placed in the notch of a semi-annular permanent magnet, and the cathode stem measurement of the parenthesis is shielded by a shield body and a part of the yoke, so there is no risk of microwave leakage. The filter case can be abolished without any problems. Therefore, not only the magnetron device can be made smaller, but also the number of parts can be reduced, and the structure can be simplified.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a magnetron device embodying the present invention, FIG. 2 is a partially cutaway plan view thereof, and FIG. 3 is a perspective view of its shield body. 1...Anode cylinder, 5...Nonmagnetic metal sealing body, 8...Cathode stem, 9...
Cathode, 10.11... Lead wire, 12.13.
...Choke coil, 18.19...Permanent magnet, 20...Notch, 21...
Frame-shaped yoke, 22... Feedthrough capacitor, 24...
...Shield body. Name of agent: Patent attorney Toshio Nakao and one other person 1-7. Ruto Goku completed ≦; Ichiku 5・-stroke if number 8・-shadow sleep kaq-ichijintotoO, If---Lee 1"! ri0-@gama1 spear

Claims (1)

[Claims] It has an anode cylinder, a cylindrical part whose tube axis is approximately L-shaped, and a flange-shaped part integrally formed at one end of the cylindrical part,
a sealing body in which the brim portion is sealed to one end of the anode cylinder; a cathode disposed within the anode cylinder along its central axis; and a lead portion of the cathode that is sealed to one end of the anode cylinder. a cathode stem led out from one end of the body and having its end fixed through the sealing body; and a semi-annular permanent member having a cutout portion disposed at the one end of the anode cylinder. comprising a magnet, a yoke that forms a magnetic circuit together with the permanent magnet, and a shield body that is fitted and held in the anode cylinder and cooperates with the yoke to shield the cathode stem and the permanent magnet, A magnetron device, wherein the cathode stem is disposed in a cutout portion of the permanent magnet.